I don't think England would have won on Saturday if Scotland had not needed an eight-point margin. We've got to say job well done for the result but Scotland played into their hands in the last 20 minutes because they felt forced to change the approach that had, until then, worked in chasing the lead that would have denied England a losing bonus point.

If that had been a Six Nations game, Scotland would have been happy with the 12-9 lead and hoofed the ball at every opportunity, leaving England chasing the game from deep in their own half. And England would have had only themselves to blame because their painfully conservative approach in the first half had left them up against it, yet again. They are in danger of losing 12-9 to somebody and coming off the field with a World Cup gone and guys like Chris Ashton thinking "I didn't even get a chance to do anything".

Martin Johnson's England have played their best rugby when their backs have been against the wall. They did it 18 months ago in the Six Nations in France, they did it last summer in the second Test in Australia having lost the first, and they did it in the Ireland game this summer after being well beaten in Dublin in this year's Six Nations. They have to find a way of breaking free of their conservative approach to play that backs-against-the-wall rugby before their backs are against the wall.

I disagree with Johnson's approach because he uses Leicester-type tactics relying on dominance in key areas such as the scrum and lineout, but this is not where England's strengths lie. The England staff would point out that winning is all that matters in a World Cup and that is what they are doing, but their performances inspire little confidence for the later stages.

The conservatism of the coaching, with its focus on doing things right and avoiding mistakes at all costs is starving England of the opportunity to play. Yet when they are forced to play with an element of risk they look a threat. You don't win anything without taking risks and Johnson has to break the shackles and encourage that in the first half-hour of games, not as a delayed reaction when England are already in a hole. Then he can allow the team to manage the last half hour of the game, depending on how things have worked out. Today they got to the last half-hour and there was no management – they just had to go for broke because they were losing.

Johnson's approach at fly-half illustrates this perfectly. In this year's Six Nations and last season's autumn internationals Toby Flood started and Jonny Wilkinson was brought on late to close things down. Now, and perhaps this is a reaction to the demoralising Six Nations defeat in Ireland that cost England a grand slam, Wilkinson starts and keeps things safe, then Flood comes on if, as against Scotland, England are up against it and need to open the game up.

This also has an impact on Ben Youngs's game at scrum-half. A running No9 such as Youngs needs to have his fly-half standing flat because if the opposition pick him up he has his No10 to pass to. But when Youngs makes five yards on a run he is then five more yards ahead of Wilkinson, who was already standing deep behind him. If the fly-half is up flat, as Flood likes to be, then the defence is kept occupied by them both and the scrum-half has an option to pass. This was perfectly illustrated by the try, when Flood stood very close to the gain line and flung out a long pass to Ashton on the wing. Wilkinson would never have been so close to his scrum-half, in this case Richard Wigglesworth, who was on for Youngs.

This is not a criticism of Wilkinson because he and Flood do different things very well, but the choice of starter illustrates what Johnson thinks. Courtney Lawes's selection in the second row is another example of Johnson's mindset. Lawes cannot read a lineout like Tom Palmer and when Palmer came on England went back to a conventional seven-man lineout. They won every single one of their own balls, and they pinched two off the opposition. Palmer can be a bit loose and can lose the ball in the off-load but that type of player can also make things happen and help win games. For England, though, the suffocating fear of doing anything wrong is stifling the chance of doing anything right.

It is difficult to know where England are in this tournament because they have won all their games and topped their group, but have struggled to put away sides they should be beating comfortably. Where Saturday's result leaves them with France next is unclear. Surely France cannot be as bad again as they were against Tonga, and I am sure François Trinh-Duc will return at fly-half, but you never know. So it is possible England will not be tested until the semi-finals, if they reach them. One thing seems certain, though,: the further they go the more likely their conservatism will be punished.

Dean Ryan played for Wasps and Newcastle and coached Gloucester in the Premiership